New Delhi: Supreme Court lawyer Dayan Krishnan has been appointed as the special public prosecutor by city police to conduct trial in the December 16 gang rape of a paramedical student who succumbed to injuries during wee hours today at a Singapore hospital.

"It is Dayan Krishnan, an eminent lawyer...He has volunteered to do it free of cost. He will be assisted by two juniors," Dharmendra Kumar, Special Commissioner of Police (Law and Order), told PTI.

The senior police officer said the harshest punishment would be sought against five accused during the trial after filing the charge sheet by January 3.

The sixth accused is a juvenile and would be tried separately at Juvenile Justice Board.

"We hope to file the charge sheet by January 3, 2013. Section 302 of the IPC, which is the penal section for murder, has been added in the FIR," Kumar said, adding, "It will be our endeavor to ensure the harshest punishment in the book for the culprits."

The special prosecutor would conduct the trial in a fast track court on day-to-day basis.

Later talking to PTI, Krishnan said, "I had given my consent to conduct the trial." Krishnan has been representing NIA, Delhi Police and other agencies at various judicial fora in many cases including the Nitish Katara murder case.

The girl, who died today at the Mount Elizabeth Hospital in Singapore owing to mutiple organ failure, was gangraped, assaulted and then dumped in south Delhi by six persons on the night of December 16.

She and her male friend had boarded the bus at Munirka around 9.45 pm on the fateful night after watching a movie.